1. Technical Field
The field of the present invention is that of water conservation measures effected using evaporation suppressant chemicals at sites including open water reservoirs and agricultural land. For effecting such measures, this invention relates more particularly to a composition comprising a blend of an inorganic constituent, selected as described hereinafter, with one or more of the higher fatty alcohols, also called alkanols, which have upwards from 12 carbon atoms per molecule. The higher fatty alcohols of use in the blend I disclose are saturated straight-chain aliphatic hydrocarbons within a range whereby in commerce they are designated xe2x80x9cdetergent range alcoholsxe2x80x9d.
For clarity as to the nature and field of my invention: the blending of specified constituents which I disclose is clearly unrelated to any special catalytic or any other chemical reaction-involving process for the chemical derivation and production of the higher fatty alcohols themselves, nor do I propose any chemical reaction between constituents of my blend, since none occurs when practicing my method of manufacturing that blend.
2. Prior Art
Scientific literature and patents have conveyed to those of ordinary knowledge in the field of water conservation both suggestions (a.) to apply higher fatty alcohols or compositions containing them to open water sites, and suggestions (b.) to apply higher fatty alcohols or compositions containing them to agricultural land. Increased public concern with prospects of global warming which might bring more drought than usual to some regions lends urgency to need for simplified attainment of civil preparedness for drought by large-scale manufacture and stockpiling of a composition that is effective for water conservation at both kinds of application sites,
One early art practitioner, W. J. Roberts, whose work for the Illinois State Water Survey Division is well known, pointed in the direction of using the same higher fatty alcohol on either open water or agricultural land.
U.S. Pat. No. 7,205,059 to W. J. Roberts (Sep. 7, 1965) teaches that xe2x80x9cwhere desired the alcohol may be applied to the soil in powdered or flake form,xe2x80x9d. Previously, regarding application to water, the same substance in the same form had been spread by Roberts on Crystal Lake in Illinois, to forestall drying up of the lake during the summer of 1957, as reported in xe2x80x9cReducing Water vapor Transport with Mornolayersxe2x80x9d, W. J. Roberts. pp. 193-201 in RETARDATION OF EVAPORATION BY MONOLAYERS, V. R. La Mer, ed., Academic Prsss (1962). Regarding application to land of xe2x80x9ctallow alcoholsxe2x80x9d such as hexadecanol and octadecanol, the Roberts patent conveys a concept respecting reduction of plant transpiration; however, I believe that, from the literal suggestion to apply powdered or flaked tallow alcohol to soil, workers of ordinary knowledge in the field today would expect that, aside from possible plant transpiration reduction, water evaporation from the soil itself likely could also be reduced by executinr the sulestiorn. Guidance in doing so need not be derivative from the Roberts patent but could rely on any and all pertinent information emergent in the past thirty-five years, supplemented by results of easily conducted experiments. One matter of guidance which I consider could be arrived at without excessive experiment is the particular amount of applied higher fatty alcohol content per acre that would be effective to conserve water in given site conditions.
Another early art practitioner, R. D. Dressler, also recognized that higher fatty alcohol blends may be applied on either open water or alricultural land.
U.S. Pat. No. 3,450,488 to R. G. Dressler (Jun. 17, 1969) specifically mentions applications of higher fatty alcohol blends both xe2x80x9cto surfaces of Large bodies of open waterxe2x80x9d and xe2x80x9con damp or moist soil in which plants are growingxe2x80x9d. Alternative methods for distribution of the blends of Dressler are reviewed in the context of the first-quoted xe2x80x9cmost importantxe2x80x9d application. Identified functional categories of optional blend additives, ie., additives aside from the fatty alcohol homoIogs of essential concern in this Dressler patent, include: xe2x80x9cdiluentsxe2x80x9d, xe2x80x9cadductxe2x80x9d forgers, xe2x80x9csolventsxe2x80x9d, xe2x80x9cdispersantsxe2x80x9d, xe2x80x9cemulsifiersxe2x80x9d, xe2x80x9csurfactantsxe2x80x9d, and xe2x80x9canti-caking agentsxe2x80x9d.
It is evident that the field encompasses a host of possible blends.
Some particular blends might lend themselves to use on both open water and agricultural land, whilst others might not. Since the Roberts patent mentioned xe2x80x9cpeat moss or mulchxe2x80x9d as possible blending materials in context of an on-land application, it is rational to then consider factors pertinent to their possible use in an open water context. For example, mulches ordinarily possess a certain property of longevity respecting resistance to major structural deterioration upon exposure to water. A mulch cannot function through a reasonably large number of alternate wetting and drying cycles on land if it lacks such longevity, as it would if it dissolved when becoming wet. It may be noted here that the term xe2x80x9cmulchxe2x80x9d in the Roberts patent is inconclusive on whether an organic or else inorganic material is intended. Inorganic materials such as sand and vermiculite have utility as mulches.
U.S. Pat. No. 3,446,571 to A. V. Oberholtzer (May 27, 1969) teaches impregnation of higher fatty alcohols into xe2x80x9cporous inert solids materialsxe2x80x9d having an xe2x80x9cadsorbent or absorbentxe2x80x9d character, The xe2x80x9cvermiculitexe2x80x9d, xe2x80x9cearth materialsxe2x80x9d, and even xe2x80x9cdirtxe2x80x9d, which are mentioned are inorganic. Sand is not specifically mentioned but would likely come to mind when thinking of earth materials and dirt. Because cellulosic materials, eg., xe2x80x9cground up stems and leavesxe2x80x9d, are also suggested in the Oberholtzer patent, like that of Roberts it fails to specify a preference as between organic and inorganic blending constituents. The Oberholtzer patent suggests distribution of the disclosed blends on collected water bodies, but one easily notes similarity of certain of the suggested blends to a blend of mulch and higher fatty alcohol. Thus, in view of the suggestion in the Roberts patent that a blend of mulch and higher fatty alcohol may be applied to soil, the supposition may reasonably be entertained that those of ordinary knowledge in the field today might perceive that many if not all of Oberholtzer""s suggested blends may be susceptible to advantageous distribution on land as well as on water.
U.S. Pat. No. 4,172,058 to J. M. Hall (Oct. 23, 1979), incorporating by reference the abovecited Roberts patent which mentioned xe2x80x9cmulchxe2x80x9d, discloses a composition comprising a blend of higher fatty alcohol with an xe2x80x9cabsorbent materialxe2x80x9d, where specified uses include application to land for the purpose of increasing retention of soil moisture. Thus, in view of the Oberholtzer patent, the supposition may reasonably be entertained that those of ordinary knowledge in the field today might perceive that the composition of Hall may be susceptible to advantageous distribution on water as well as on land.
Probably a number of other higher fatty alcohol containing compositions, suggested by their respective inventors specifically for suppression of evaporation from open water surfaces, might be perceived by workers of ordinary knowledye in the field today as possibly distributable on land, including compositions known from three patents next identified, each of which, in common with the others, as well as with the Oberholtzer patent, mentions that the higher fatty alcohol constituent may be melted in order to facilitate blending with another constituent.
U.S. Pat. No. 3,391,987 to L. E. Myers (Jul. 9, 1968) discloses manufacture of a composition by melting a higher fatty alcohol and blending the same with a xe2x80x9cmatrixxe2x80x9d or xe2x80x9c,carrierxe2x80x9d selected from water-soluble saccharides. Regarding molded blocks of the comnposition intended for siting underwater and which require a density greater than that of water, the Myers patent states: xe2x80x9cWhere greater density is desired a dense material such as powdered calcium or barium sulphate, ground rock, sand, etc. may be incorporated in the composition.xe2x80x9d
U.S. Pat. No. 3,415,614 to R. R. Elan and S. R. Sheeran (Dec. 10, 1968) discloses manufacture of a composition which xe2x80x9cfloats on waterxe2x80x9d by melting a higher fatty alcohol and blending the same with a xe2x80x9cspreading agentxe2x80x9d selected from water-miscible liquid heterocyclic compounds such as tetrahydrofuran and tetrahydrofurfural alcohol.
U.S. Pat. No. 4,250,140 to J. J. Rowlette (Feb. 10, 1981) discloses manufacture of a composition by melting a higher fatty alcohol and blending the same with water soluble polyethylene glycol, preferably grinding the cooled result, then admixing the same with a xe2x80x9cfillerxe2x80x9d material selected for capability of xe2x80x9cgIenerating a gas upon contact with waterxe2x80x9d, eg., sodium bi-carbonate.
Unlike the specified organic blending material in the Hall patent, all essential materials specified for blending with a higher fatty alcohol in the foregoing three patents intentionally lack the longevity of a mulch.
I have not located, in the field of water conservation involving use of blended compositions containing higher fatty alcohols, whether for application to land or open water, any clearly equivalent blend to that which I hereinafter disclose.
However, from U.S. Pat. No. 3,980,490 to G. L. Schneider (Sep. 14, 1976), which I regard as a patent from outside the field of my invention, there is suggestion of a xe2x80x9csoil stabilizing agentxe2x80x9d that can be made by a proposed chemical reaction that involves a source of calcium, irncluding calcium hydroxide or calcium sulfate, plus a source of sulfuric acid, plus water, and plusxe2x80x94optionallyxe2x80x94a hydrocarbon material selected from eight itemized xe2x80x9coilsxe2x80x9d ranked by Schreider in descending order of preference from xe2x80x9c(1) kerosenexe2x80x9d to xe2x80x9c(8) residual fuel oil or asphaltxe2x80x9d. I note that the least preferred optional hydrocarbon is the one closest in general character to the higher fatty alcohols, not expressly mentioned.
What the Schneider patent teaches regarding functions of the xe2x80x9creaction productxe2x80x9d it discloses appears incompatible with water conservation at a site of land intended for normal agricultural crop-growing. As a xe2x80x9cstabilizing agentxe2x80x9d added to soils, the Schneider xe2x80x9creaction productxe2x80x9d serves inventive objects with functions: (a.) xe2x80x9cto reduce the speed with which moisture leaves during periods of dehydrationxe2x80x9d; and (b.) xe2x80x9cto restrict the speed with which if water enters the structure of such soils during periods of wet weatherxe2x80x9d.
Incompatibility of the (b.) function with a leading principle with which workers of ordinary knowledge in the field of Tmy invention are acquainted is demonstrable by reference to a statementxe2x80x94clearly in a context of seeking benefit to agriculture by applying evaporation suppressants to soilxe2x80x94that warns away from adding to soil, together with an evaporation suppressant, an agent that impairs water infiltration. This statement is by F. D. Mistry and M. E. Bloodworth in Publ. No. 62 of the international Association of Scientific Hydrolory (1963), at p. 61: xe2x80x9cThe use of chemical copounds in reducing evaporation, from a practical standpoint, will be ineffective if water infiltration is impaired.xe2x80x9d Restriction of speed of entry of water into soil by the Schneider xe2x80x9creaction productxe2x80x9d, ie., xe2x80x9csoil stabilization agentxe2x80x9d, is the same thing as impairing water infiltration. Thus, it is likely that workers of ordinary knowledge in the field of my invention would dismiss out-of-hand the Schneider invention as inapplicable to procuring the benefit to agriculture they seek.
Aside from which, while granting that the Schneider invention suppresses evaporation from underlying treated soil by providing a water-resistant top layer, it strains credulity to suppose that easily conceived departures from the Schneider invention would render it advantageously applied to an open water surface. The closer-in-art patents cited above, but not the Schneider patent, would sustain attention of someone of ordinary knowledge in my invention""s field.
A supposition has been above entertained that certain patents disclosing evaporation suppressant compositions for application to open water warrant being looked to for compositions of possible applicability to agricultural land, and vice versa. This supposition, however, does not affirm that any of the specific blends respectively proposed in the patents of Oberholtzer, Hall, Myers, Egan et al, and Rowlette would necessarily prove effective if transposed, in application from the one type of site described, to the other, unuescribed. Of all the patents I have cited, only ore explicitly suggests applicability of a disclosed blend both to open water and agricultural land, viz., that of Dressler, which also is the one mentioning the largest number of optional methods of application and composition additives.
A respect in which I regard the whole field of prior art to be generally deficient is paucity of information on whether normally designated specific functions of given constituents remain effective in the case of transposed application siting. For example, the Dressler patent mentions, on the one hand, possible use with the disclosed composition of xe2x80x9cemulsifiers such as nonionic or anionic organic surfactantsxe2x80x9d, and, on the other hand, using the composition for application on xe2x80x9csnow fieldsxe2x80x9d. I doubt that ordinary workers in the art would comfortably accept from these bare suggestions of Dressler that the surfactants mentioned retain similar emulsifying effect in higher fatty alcohol blends placed on snow, that they have in blends on open water. As another example, a somewhat difficult experiment might be needed, to verify what, if any, useful effect of underground gas fizzing attends possible burial in moist dirt of a sodium bi-carbonate containing composition of Rowlette, which when xe2x80x98buriedxe2x80x99 underwater hasxe2x80x94for the sodaxe2x80x94functions of first breaking off from a submerged tablet a fatty alcohol containing particle, and then of hastening its dispersal aloft to the water surface.
My opinion is that equivalent utility-functions for the same substances are not properly viewed as xe2x80x98inherentxe2x80x99 when application sites which are in major respects different from one another are proposed.
Therefore, in my disclosure to follow of a novel water-saving blend that is peculiarly well adapted to use both on open water and agricultural land, not the least aspect of my contribution to advance of the art may be that T expressly include indications of where functions of my proposed constituents remain the same, and where not.
A major object of this invention is to simplify the task of those who are responsible for civil preparedness in prospect of droughts, by providing instruction how to make and use a single water-saving composition which is peculiarly well adapted both for application to agricultural land, and for application to open water surfaces of reservoirs storing water in bulk. By xe2x80x9cagricultural landxe2x80x9d I mean to include soil plots intended for normal crop growth both before and after establishment thereon of the crop.
Another object of the invention is to provide a versatile water-saving composition that is easily distributable at the two kinds of contemplated application sites, using a variety of distribution techniques and uncomplicated equipment.
Further objects, including suggestions how to meet certain technical challenges and procure several advantages as detailed further below, will become apparent as disclosure of the invention proceeds.
Searching for a composition of peculiarly well adapted character respecting both kinds of contemplated application sites began in awareness that two of the larger tonnage inorganic substances in normal supply to current agriculture are lime and gypsum. The latter, as calcium sulphate, was mentioned in the prior art evaporation retardant of Rowlette, where its use was suggested for provision of weight to submerged tablets. For reasons explained further below, plain gypsum is unsuitable for use in the higher fatty alcohol containing blend I disclose.
From extensive experimentation conducted in secrecy, I have discovered that about one part by weight of a constituent comprising one or more higher fatty alcohols having upwards from 12 carbon atoms per molecule should be admixed while in the liquid-phase acquired by melting with about ten parts by weight of either pre-powdered slaked agricultural lime, or alternatively, finely crushed gypsum into which sulfuric acid has previously been mixed in approximately a ratio equivalent to 5 milliliters per 300 grams. Hereinafter I will sometimes call the specially made gypsum containing constituent xe2x80x9cacidified gypsumxe2x80x9d.
Which of the two alternative non-alcohol constituents proposed should be selected for a particular batch of composition, or which of the two embodiments of the invention should be used or stockpiled in a certain region, depends in a simple manner upon the pH requirements of intended sites of application. A site which would benefit more from an alkaline treatment receives the lime-containinq blend, and a site which would benefit more from an acidic treatment receives the blend that contains the acidified gypsum.
The most important function of sulfuric acid in the acidified gypsum is not, however, the function of providing a blend constituent making the blend suitable for application to a site benefitting from an acidifying treatment. Gypsum which has not been pre-treated using sulfuric acid is not suitable for direct substitution in place of slaked agricultural lime as the calcium containing constituent of a water-saving composition in accordance with my invention.
Briefly explained, the unsuitability of plain calcium sulfate into which sulfuric acid has not been pre-mixed relates to a unique manner of promoting dispersal apart from one another of individual particulate aggregations of the calcium hydroxide containing original embodiment of the invention. In contact with water, the lime portion of each such aggregation commences dissolving with release of hydroxyl ions that diffuse much faster than calcium ions. This differential of ionic celerities results in acquisition by individual particulate aggregations of like charges, producing their mutual repulsion on or in water. Readily appreciated advantages resulting from this novel mechanism include: enhancement of film spreading on a water surface; and reduction of apparent viscosity for possible water suspensions and slurries distributable either on open water or land surfaces. The kind of xe2x80x98imbalancedxe2x80x99 release of ions involved is unsuggested in the prior art.
I doubt that the problem of unsuitability of plain gypsum as a substitute for lime in my composition would even be raised as a problem in the mind of anyone unfamiliar both with the aforesaid charge acquisition mechanism and with my invention in its original slaked lime containing embodiment. Once recognized though, I found the problem resolvable by using sulfuric acid to overcome deficiency of slow-dissolving plain gypsum at providing effective extent of imbalanced ion diffusion rates, Particulate aggregations containing acidified gypsum particles adherent to higher fatty alcohol constituents perform similarly as the lime containing aggregations and are produced in accordance with the same processing conditions.
The temperature of the higher fatty alcohol melt during blend manufacture should be from about 90xc2x0 C. to 120xc2x0 C. until thorough mixing of constituents in the already indicated ratios is achieved. A cooling step follows in which the temperature of the blend is lowered to at least 30xc2x0 C.
The resulting composition in either of its two embodiments may, due to uneven stirring events, contain lumpy pieces which are readily reduced by any known means to provide a non-lumpy reasonably fluent particulate consistency. Acceptable cross-sectional dimensions of the irregularly shaped individual particulate aggregations produced range between about 10 and 300 microns. The finished product is a powdery composition which is easily distributed in dry form upon both land and water surfaces by any known powder distribution technique, such as uses blowers, agricultural dusters, agitated gravity-fed powder dispensers and hoppers, etc. If water, water pumping, and piping means are available, it is feasible to make a suspension or slurry adapted to distribution of the composition in manners known in the art for suspensions and/or slurries. My invention obviates need for costly emulsifying agents to prevent equipment clogging, because the composition aggregations repel one another when in water. I also wish to avoid use of emulsified higher fatty alcohol in compositions applied to land, for a reason brought out further below, concerning water infiltration.
Extended droughts could bring periods of scarcity of higher fatty alcohol and water supplies, when distribution of minimal dry blended higher fatty alcohol content per acre upon land sites is indicated, in which case an expedient not of the essence of the invention, but helpful, is to dilute the the particulate composition of the invention with a larger quantity of cheap non-reactive material such as sand, or even dry earth materials available in a drought-stricken vicinity. Using inorganic rather than organic substances as non-alcohol blending constituents of a water-saving composition is also attuned to a prospect of drought of extended duration, when organic materials used in certain prior art compositions, eg., the saccharides of Myers, furans of Egan et al made from oats, and starch in Hall""s invention may become scarce, making it better to reserve sugar, oats, and starch supplies for feeding the drought-affected human population, since these substances are not essential for conservation of water.